Combined facsimile transmitter recorder



June 20, 1950 F. E. DHUMY ETAL 2,511,837

COMBINED FACSIMILE TRANSMITTER RECORDER Filed Jan. 21, 1947 14 Sheets-Sheet 1 INVENTORS F. Ev dHUMY HP. CORWITH RD. PARROTT BY F.l O'BRIEN TTO NEY June 20, 1950 F. E. DHUMY ETAL COMBINED FACSIMILE TRANSMITTER RECORDER i4 Sheets-Sheet 2 Filed Jan. 21 1947 FIG. 3

INVENTORS F. E.d'HUMY HP. CORWITH R.D. PARROTT BY F'.L.. O'BRIEN ATTOR N EY June 20, 1950 F. E. DHUMY ETAL 2,511,337

COMBINED FACSIMILE TRANSMITTER RECORDER Filed Jan. 21, 194'! 14 Sheets-Sheet 3 FIG.4 7a

' INVENTORS F E.dHUMY 0 86 INVENTORSI H.F?CORWITH R.D.PARROTT ATTORNEY June 20, 1950 F. E. DHUMY ETAL COMBINED FACSIMILE TRANSMITTER RECORDER Filed Jan. 21, 1947 14 Sheets-Sheet 4 H F? CORWITH R. D. PARROTT F. L. O'BRIEN ATTORNEY June 20, 1950 F. E. DHUMY EIAL 2,511,837

COMBINED FACSIMILE TRANSMITTER RECORDER Filed Jan. 21, 1947 F'IG.6I

14 Sheets-Sheet 5 72 ISI I50 F: E. d'HUMY INVENTORS: H.F? CORWITH R.D.PARROTT BY F.| .O'BRIEN ATTORNEY June 20, 1950 F. E. DHUMY ETAL 2,511,337

COMBINED FACSIMILE TRANSMITTER RECORDER Filed Jan. 21, 1947 FIG.7

l4 Sheets-Sheet 6 IV fil I 64 VENTORS F. E.d'HUMY H.F?CORWITH R D.PARROTT BY F.L.OBR|EN ATTORN EY June 20, 1950 F. E. DHUMY EI'AL COMBINED FACSIMILE TRANSMITTER RECORDER Filed Jan. 21, 1947 14 Sheets-Sheet 7 F l G 8 F. E. HUMY l3 INVENTORSI H.P. CORWITH R. D. PARROTT F. L. O'BRIEN w zw TTORNEY June 20, 1950 F. E. DHUMY ETAL 2,511,337

COMBINED FACSIMILE TRANSMITTER RECORDER Filed Jan. 21, 1947 14 Sheets-Sheet 8 FIG.9 E

SK so ,1

INVENTORS F. E.dHUMY H. PCORWITH R.D.PARROTT BY F.L.OBRIEN TORNEY June'20, 1950 F. E. DHUMY ETAL 2,511,837

COMBINED FACSIMILE TRANSMITTER RECORDER Filed Jan. 21, 1947 14 Sheets-Sheet 9 INVENTORS E. dHUMY F. CORWITH D. PARROTT BY L. O'BRIEN iTTORN EY H. R. F.

June 20, 1950 Filed Jan. 21, 1947 FIG.

F. E. DHUMY EI'AL COMBINED FACSIMILE TRANSMITTER RECORDER 14 Sheets-Shut 10 19 82 g ea [81 182 -l-NVENTORS |a4 F. E.dHUMY H. F? CORWITH R. D. PARROTT BY F. L.O'BRIEN Y June 20, 1950 F. E. D'HUMY ET AL COMBINED FACSIMILE TRANSMITTER RECQRDER l4 Sheets-Sheet 12 Filed Jan. 21, 1947 FIG.I4

INVENTORS F. E. dHUMY H. F. CORWITH R. D. PARROTT F. L.OBRIEN TTORNEY F. E. D'HUMY ETAL COMBINED FACSIMILE TRANSMITTER RECGRDER June 20, 1950 14 Sheets-Sheet 13 Filed Jan. 21, 19 47 .F'IG. I9

FIG. 20

INVENTORS F. [.dHUMY H. P. CORWITH R. D. PARROTT F. L. O'BRI EN ATTORNEY Patented June 20, 1956 COMBINED FACSIMILE TRAN SMITTER- RECORDER Fernand E. dI-Ium-y, Scarsdale, and Howard P.

CorWith, New'York, N. Y., and Robert D. Par- .rott, West New York, andEredeI-ick L. Brien, Rutherford, N. J., assignors to The Western Union Telegraph. Company, New York, N. Y., a

corporation ,of New York Application January J21, 1947, Serial No. 723,322

26.,Glaims. 1

This invention is fora novel facsimilemachine primarily adapted to operate as aduplicator but also capable of being used simply as a transmitter or as a recorder.

The main object of our invention, is to provide a facsimile machine for'quickly making duplicates of any desired subject matter appearing on a sheet, such as typewriting, maps, fashion plates, drawings, newspaper articles, or any kind of graphic record adapted for scanning in our machine.

In facsimile duplicators heretofore devised it was necessary to have at least two horizontal scanning cylinders mounted in axial alignment, one for transmitting, the other for recording. The subject sheet and the recording blankwere wrapped around the outside of the cylinders.

From a commercial standpoint a machine like that was objectionable for several reasons. In the first place, the. tandem arrangement of the cylinders resulted in a machine of undue length, as can be seen, for example; in Fig. 2 of, the OBrien and Estes Patent No. 2,260,862,-granted October 28, 1941. A machine of-such proportions would not be suitable as a piece of office equipment. Then,'t0o, the mounting of the sheets on the outside of the cylinders requiredcare and time because the sheets had to be wrapped around the cylinders withtheir edges coinciding. Finally springs had to be rolled over those sheets to hold them in place.

To overcometheforegoing and other disadvantages in facsimile duplicators of prior design, we have invented a machine of that type which is compact in structure and is easily loaded with the required sheets. The principal feature of our machine comprises a vertical transparent cylinder in which the original or subject sheet and a recording blank are deposited for scanning. 'It

is only necessary to arrangethe two sheets back to back, roll them up with the original sheet on the outside and drop them into the cylinder. An optical carriage outside the cylinder scans the copy sheet and an electric stylus inside the cylinder records the scanned copy on the xposed surface of theblank. In a; preferred formof our machine We use but a single motor forrotating the cylinder at high speed and operating .both scanning devices air-low speed. The driving connections for the scanning devices comprise a novel Windlass arrangement which is far simpler and cheaper than the lead screw and half-nutdrive heretofore employed forscanning.

By mounting the scanning cylinder vertical in our machine we canuse a cylinder of unusual length without increasing the horizontal dimensions of. the machine, which is thereby capable of 2 handling large sheets. Since the same cylinder holds both sheets, the transmitting and recording mechanisms always operate on their respective sheets in phased relationship without the need of separate phasing connections. In other words, our machine is self-phasing so that the operator need only align the two sheets before rolling them up and he can dropthem into the cylinder preferred embodiment of our invention. In these drawings:

Fig. 1 is a front elevation of the complete machine;

Fig. 2 is a plan view of Fig. 1;

Figs. 3 and 4 together represent a front view of the inside mechanism, these two views joining along the line A-A;

.Figs. 5 and 6 togethershow the inside mechanism as viewed from the left of the machine, these two viewsjoining along the line B- -B;

Figs. 7 and 8 together show a rear view of the mechanism, it being assumed that these two figures join along the line C-C;

Fig. 9 is a cross-section on line 9-9 of Fig. 3;

Fig. 10 is a cross-section on line i 0I t of Fig. 4;

Fig. 11 Ba longitudinal section on line l|.-ll of Fig. 2;

Fig. 11A shoWsa detail at the base of the scanning cylinder;

Figs. 11B and 11C are top and side views of a detail pertaining to the cover of the cylinder;

Figs. 12 and 13 show the positions of the two scanning devices respectively at the beginning and at the nd of the scanning operation, these views being simplified for clearness;

Fig. 14 represents an enlarged cross-section on line [4-44 of Fig. 11;

Fig. 15 is adetached perspective of the recording head on the same scale as Fig. 14

Figs. vl6'and- 17 show details ofth recording head;

Fig. 18 illustrates how the-two sheets are rolled up for insertion into the scanning cylinder;

Fig. 19 is a schematic illustration ofthe driving connections for the two scanning devices;

Fig. 20 shows one of the-brackets used in the machine; and

Fig. 21 is a diagram of the operational circuits of the machine.

3 As shown in Fig. 1, the machine is mounted on a cabinet I ll whichcontains the various electrical units and connections required for the circuits of Fig. 21. The operating mechanism of the machine is supported as a unit on a base plate :2

The vertical cylinder and its mounting The sheets to be scanned are placed in a vertical transparent cylinder H which may be of glass or any other suitable material that is optically clear.

The cylinder I! is mounted in vertical position for rapid rotation and since we prefer a cylinder of considerable length it is necessary to support it in bearings at both ends. The rotary mounting of cylinder I1 is best shown in Fig. 11 to which We shall now refer.

A horizontal plate l8 which projects from an upright support [9 carries a bushing 2!] tightly fitted in place. A short sleeve or hub 2| extends through the bushing 20 and is journalled therein for rotation. A collar 22 is secured to the upper end of hub 2| over the bushing 20 by a split ring 23 or. otherwise. The two annular members 20 and 22 enclose ball-bearings 24 to provide smooth easy rotation of the hub 2|. To reduce the noise of operation the collar 22 may be of non-metallic material, such as Bakelite. An annular gear 25, preferably non-metallic, is secured to the lower end of hub 2| by screws 26 and forms a driving connection for the hub, as will be explained later.

The cylinder ll fits into the rotary hub 2| and rests at its bottom edge on an annular shoulder 2! inside the hub. A pin 28 in the hub enters a bayonet slot 29 in the cylinder (see Fig. 11A) when the latter is pushed down on the shoulder 21. The cylinder may then be turned backward until it is stopped by the pin 28 or it may be left without giving it a backward twist because the initial rotation of the hub 2! will carry the pin forward to the locking position 28. The cylinder I! is thus firmly locked to the hub 2 I, yet is easily removable when necessary. It will be seen that the pin 28 acts as a direct coupling between the hub and the cylinder, so that the two always rotate as a unit.

The upper end of cylinder ll carries a metal ring 30 which is journalled in an annular bearing member 3|. The ring 30 is cemented or otherwise secured to the outer surface of the cylinder so as to project beyond the top edge of the cylinder. This projecting portion of the ring carries a friction band 32 which forms in effect a continuation of the cylinder wall. The band 32 may be of any suitable material with a friction surface, such as rubber, leather, cloth, and the like. We may also make the band 32 of metal (attached to or integral with ring 30) with its inside surface knurled or otherwise roughened to produce a frictional contact. As will be explained later, the function of the friction band 32 is to hold the upper edge of the inserted sheets against slipping when the cylinder rotates.

The base end of cylinder ll carries on the inside a ring 33 of good conducting material, such as brass. This ring can be readily fixed in place by a suitable adhesive like shellac, and an additional binding effect is-had by putting a circular groove 34 in the outer wall of the ring. After an adhesive coating has been applied to the cylinder, the tightly fitting ring 33 is forced into the cylinder and some of the adhesive will collect in the groove 34 where it will harden and form a locking joint between the cylinder I! and the ring 33. In the present instance, the inner wall of the ring 33 is longitudinally grooved as indicated at 33' for a purpose that will be explained in due course.

The top edge of ring 33 is bevelled to provide a peripheral groove or channel 34 which slopes downward to the cylinder wall. The function of channel 34 is to support the lower edge of the inserted paper sheets 35 and 36. Before being inserted the two sheets are lined up back to back, then rolled into a tube (see Fig. 18) and pushed down into the cylinder until the lower edges of the sheets rest in the channel 34. The slope of this channel not only guides the inserted sheets outwardly toward the cylinder wall but looks them against inward displacement.

In the present machine, the outer sheet 35 is the subject or copy bearing sheet and the inner sheet 36 is a blank on which the transmitted copy is recorded. The blank 36 may be any type of recording paper suitable for use with an electric stylus, as is well known in facsimile work. It is necessary to ground the sheet 36 during the recording operation and that ground connection is formed by the metal ring 33 which the lower edge of the sheet touches. Although the sloping channel 34 is interrupted by the grooves 33, that does not interfere with the described functions of the metal ring 33.

The nested sheets 35 and 36 must be held firmly against the cylinder wall at their upper edges and the inner recording blank 36 should also have its upper edge grounded in addition to the lower. For this purpose we provide a heavy metal ring 31, preferably of bronze, which is carried loosely by a cover 38 (Figs. 5 and 18). The ring 3'! is split into two sections which are hinged together by a pin 39 as shown in Figs. 11B and 11C. The free ends of thetwo ring sections are separated by an irregular line, as indicated at 43 in Fig. 5, so that the two hinged sections will overlap even when they move slightly apart. This overlapping arrangement is also used at the hinged ends of the half-rings, as shown in Fig. 11C. The split ring 3'! is loosely held in the cover 38 by set screws M which project into an annular recess 42 of the ring, whereby the latter is free to adjust itself radially and vertically. A light spring blade 43 of brass or copper is secured to the cover 33 so as to be in constant pressure contact with the-ring 31 and maintain a good ground for the same.

The dome-like cover 38 has ventilating slots 44 and is provided with an arm 45 hinged to a block 43 by a pin 41. The block 45 is mounted on a horizontal top plate 48 which extends across the machine (see Fig. 7) as part of a main supporting standard 49. As shown in Figs. 8, 9 and 10, the upright section of this standard, which may be a single casting, is a right-angled plate and the bottom piece 56 of the casting is secured to the base I2 of the machine by screws or bolts 5|. For additional rigidity we provide the standard 49 with a forward extension 49' (Figs. 4 and 10) which overlaps the vertical support [9 and is secured thereto by screws 49a or otherwise.

Referring to Fig. 5, the annular bearing member- 31. previously descr bed. my be an m esnl extension, of theton plate 48 or secured re o as a separate part. The cover 38, a 52 to which the spring contact I may be at,- tached. When the cover 38 is closed, the handle 51 rests on a rubber button 53 on the ring 3|. this button holding the cover and the split ring 31 in horizontal position. It is desirableto have thering 3i and the cover 38 of an attractive design because they are leftexposed by the l5, asshown in Fig. l, and are part of the out. side-appearance of the .Asse'en in Fig. 11. the split ring 3] carried by the cover 38 has a lateral shoulder it, and a lie-- pending cylindrical flange 55. When the cover 38 is thrown back. the top of cylinder I1 is entirely cleared for the. insertion of sheets 35 and 36, as illustrated in Fig. 18. When the cover is closed down over the loaded cylinder, the split ring 31 occupies the position shown in Fig. 11, with the shoulder 54 resting on top of the cylin-. der. and the cylindrical flange 55 just touching (or nearly touching) the inserted sheets. The ring 3 drops naturally into this position by its own weight and because of its, loose mounting. When the cyl nder [1 is rapidly rotated for scan-- as will presently be describedthe heavy ring, 31 rotates with it and the pivoted i'ins sections fly; outward by centrifugal force. thereby press ing against the sheets 35 and.. 36 and holding them firmly against; he friction 3.2. The overlapping portions of the spread ring sections 31 providea continuous contact with the paper.

It should be noted in Fig. 11v that the ring 37 is in contact with the top edge of the electric recording sheet 36. so that the ring. forms a ground for the sheet ailhat end. The inner sheet 36 is therefore effectively grounded at both ends for the most satisfactory results of the re. cording operation. It clear that the ring 31; performs the dual function of clamping the sheets tight. against the rotating cy nder and acting as a. ground connection for the recording; circuit.

The optical scanning mechanism The outer sheet 35 as previously out, bears the subject matter to be duplicated on the inner blank 36. The rolled up nested sheets are so inserted that the copy on sheet 35 is right side up and n h outside of the D e ube. as mor sented in Fig. 18. The copyis scanned optically throu hthe cylinder wall from. the ton down while the c linder 11 rotates in a cl ckw se di rection.

A Scan carria e indicated as. a unit by SK is arrangedat. the back of the. machine to Slide downward slowly behind the rotating cylinder 11 dir ting. a. sp t of light a ai st. the copy sheet 35;.- ce. the scanning carriage 5154 substantially like the scanning carriage. d sclosed in; th pending: application. of, Wise et a1... Ser. No. 65%Q'Z4, now Patent No. 23,503,311, granted April 11;, l950, we need not describev it; in. detail. It will be sufficient; to say that this unit comprises a. U,- shaped sheet metal frame 56. (Flu- 9) on which are mounted the usual, parts of an: optical; scan: ner, namely. an exciter lamp-'51. 8- condensing tube 58, a, pickup tube 58'. a photocell 50. a. chopperdislc 61. and a. small synchronous motor 52. for driving the. disk. The. functions and operative relation of: those parts are so.- well known as to require no further particulars.

To the front wall of the carriage frame n is secured along sleeve 61 which. slides on a rod 04,; supported between the It and the tip;

t8. -The sleeye 63 is preferably welded to the carriage frame. Topreyent twisting of the carriage in its movements we provide the same with a. side bracket i5 (Figs. 5 and 9) arranged to enclose a vertical guiderod 66 in a snug slidable fit. The guide rod 65 is behind the rod 64 and. extends between the base I! and the top plate 48.

The scanning carriage SK is normally held in uppermost or starting position by a pair of spring drums and 68 which are of well known construction and therefore require no description. The upperspring drum 6'! is pivoted on a, bracket 59 (Fig. '1) which isattached to the vertical plate can A cord or tape in wound on the drum 51 is connected to a slanting arm H which projects from the carriage frame 55. The lower spring drum 5g is pivoted on a bracket 12 mounted on the base l2. (Fig. 8) A cord or tape I3 wound on dr -um 68 passes upward over a pulley 14 (Figs. 3 and 5) and is connected to the carriage frame by a pin or screw The pulley I4 is mounted on a braoketio depending from the top plate 48.

. The springs in the drums 61 and 68 are so arranged that normally they hold the carriage SK up When the carriage moves down during scanning (as later to be described), the cords 10 and I3 wind up the spring drums so that upon release of the carriage they quickly pull it up to starting position. A rubber buffer 11 on the upper end of rod 5d forms a silent stop for the carriage. Having thev drum connections on opposite sides of the carriage frame 56 causes the latter to slide smoothly up and down.

' The electric recording head The inner surface of the recording sheet 36 is scanned by an electric head of novel construction mounted inside the cylinder l1. It will be convenient to identify this recording head as a unit by the letters RD. Referring to Fig. 11, the recordinghead slides up and down on a fixed metal post 78 extending centrally through the cylinder H and supported independently thereof. The post- !8 is square or rectangular in cross-section to prevent turning of the recording head thereon. 'Asshown in Figs. 10 and 11, the lower endof postlfi is fixed on a bracket 19 which has a recessSilfor receiving the post in a tight fit. One or more screws 8| hold the post rigidly in place.

The bracket 19 projects laterally from a vertical plate 82' towhich it is fastened by screws 83. The plate 82 is here shown as part of a casting which a-lso includes the upright wall [9 and the horizontal plate l8 projecting laterally therefrom to-sup'port the rotary mounting for the cylinder, as previously described. A web 84 connects the parallel upright members I9 and 82, as can be seenin Figs. 4 and 10, and a wide foot piece 85 oi the casting rests on the main base l2 to which it isseoured' by screws 86.

Referring to Fig. 11, the fixed square post 18 extends through bothends of the rotary cylinder it without in any way interfering with the rotation thereof: nor with the insertion and removal of the sheets. The recording head RD is so constructed: as; to fit snugly around the post 18' for smooth movement up and down. within the cylinder. The novel structural details of the recording; head are fully shown in Figs. 14 to 17 which we; shall now describe.

A block. 81 of insulating .material, such as Bakelite, hasa. right angled recess 88 adapted to enclose; two. sides of the square post 18. A right angled metal plate; 88; is secured to the. block 81 15. bVriScEQwS 90in such position as to surround the the cord-I34 is wound to lift the recording head,

and it should be noted that the drum is sufficiently long to require only one layer of cord to be wound up. This is shown in Fig. 13. The practical result of this single layer of cord on the drum is the winding up of the cord at the same linear speed so as to produce a uniform upward motion of the scanning head RD. It will be seen that the winding drum I35 and the flexible connections I24 and I34 constitute a simple form of winch or Windlass arrangement for raising and lowering the scanning devices SK and RD.

Referring toFigs. 6, l and 11, the drum I35 is mounted loosely on a shaft I36 which is jouriialed in a bracket I31. The particular form of this bracket is shown in Fig. 20 where it will be seen'that the bracket is a substantially L-shaped structure with a horizontal top bar I38, a vertical'end post I39, a, base section I40, and an intermediate arm I4I which connects the top with the base section. A rectangular recess I 42 formed by the shape of the arm I4l makes room for a part to be described later on. The bottom piece I40 of bracket I 31 rests on the main baseplate I2 to which the bracket is secured by screws I43 and M3. There is no single figure showing both screws but we may point out that the screw I43 (Fig. 6) goes into a hole I45 in Fig. 20, and the screw I44 (Fig. 9) enters a slot I46 in the bracket base I it. The rotary shaft I 36 passes through aligned openings I41 and I48 of bracket I31. In other words, the drum shaft I36 is supported at one end by the post I39 and at a midway point by the arm I4l.

A helical gear I49 is fixed on shaft I36 between the bracket members I39 andI4I (Fig. 10) and this gear is permanently in mesh'with a helical worm or pinion I50 mounted on a cross shaft II. An electric motor I52 is mounted in vertical position on the upright bracket plate 82 by screws I53 (Figs. 9 and The upper end of the motor shaft I54 carries a pinion I55 in mesh with the gear 25 of the cylinder mounting, as shown in Figs. 4, 6 and 9. The lower end of the motor shaft goes into a reduction gear case I56 (Figs. 10 and 19) where thecross shaft I 5| is connected to the motor shaft in a reduced gear ratio of predetermined degree. Since the reducing gears in case I56 are a well known drive assembly it will not be necessary to show or describe any details thereof.

Referring to'Fi'g. 6, the winding drum $35 is connected to the motor-driven shaft I36 by a clutch I 51 which comprises 'a'toothed ring I58 slidably keyed to the shaft and a complementary toothed ring I59 fixed to the adjacent end of the drum. The slidable clutch ring I58 is operated by a yoke I60 which is pivotally mounted on the rear or inner end of bracket I31 by a pin I6I. As best shown in Fig. 13., the arms of yoke I66 surround the clutch ring I58 and carry screws or pins Hi2 to enter a peripheral groove I53 in the rotary clutch ring, whereby the latter is connected to the yoke for slidable operation. This does not interfere with the rotation of the clutch ring I58.

- Thepivoted clutch yoke I60 is operated by a solenoid H4 mounted on the main base I2 be heath the arm' I33 of bracket I31. The rectangular recess I42 of this bracket permits the placing of solenoid 54 beneath the drum I35 (Fig. 6), therebyadding to the compactness of the machine. The corev [650i thesolenoid-is 10 connected to the lower end of oke I63 by a pin or screw I66. A contracting coil spring I61 is connected at one end to the screw IE6 (or to any other part of the yoke I60) and its other end is connected at I68 to a suitable fixed support, which in this case happens to be the bracket 12. The spring I61 normally pulls the yoke I 60 rearward '(to the left as viewed in Fig. 6) to hold the clutch ring I58 away from the companion ring I59 on the drum I35. A suitable stop limits the movement of yoke I63 by the spring I61. In Fig. 6, the lower end of the yoke abuts against a socket I69 in which the bottom or the guide rod 64 is mounted.

In Fig. '6 we call attention to a coil spring I10 mounted on the shaft I36 between the clutch members I58 and $59. This coil spring normally expands and tends to 'push the drum to the right (as viewed in Fig. 6) against a fixed disk or washer I1I on the bearing arm I4I of bracket I31. The drum I35 is "so mounted on shaft I36 as to have a slight sliding movement thereon sufii-cient to enable the coil spring I10 to push the drum against the washer I1I. This pressure contact between the rotary drum I35 and the fixed washer I1I acts as a brake for the drum to prevent unwinding of the cord I 34 too fast when the recording head RD descends rapidly after a scanning operation. This will be more fully iinderstood from the detailed description set forth under the next heading.

Operation of scanning carriage SK and recording head RD When the attendant of the machine rolls up the paper sheets 35 and 36 for insertion into the cylinder I1 which always rotates clockwise, he rolls them up in such a way that the sheets overlap as illustrated in Figs. 14 and 18. That is to say, the inner overlapping end 36 trails in the direction of rotation of the'c'ylinder so that the stylus can ride off the vertical shoulder I12 formed by the inner edge of the nested sheets. When the paper tube thus formed is pushed down into the cylinder I1, the bell-shaped cover I I6 of the recording head RD expands the sheets radially outward and their lower edge automatically drops Into the bevelled channel 34 which cooperates with the flange I22 of the cover to hold the lower portion of the sheets firmly against the inner wall of the cylinder.

If the recording sheet 36 has no heading and i entirely blank, it makes no diiference which way this sheet is put in, but if it has a printed heading this comes at the bottom when the sheets are arranged for insertion, while the heading on sheet 35 is at the top. Thus, in Fig, 18 it will be seen that the copy sheet 35 is placed with its heading 3511 on top, whereas the recording sheet 36 is inverted to have its heading 36a at the bottom. Let it be understood that when we refer to the sheets 35 and 36 as paper we use that term in the description and the claims in a broad sense to include any sheet material capable of receiving copy and adapted to be scanned in a facsimile machine.

Having inserted the sheets, the attendant closes the cover 38 and presses a button I13 which projects out of the casing I 5, as seen in Figs. 1 and 2. The push button I13 operates a switch I14 carried by a bracket (Figs. 4 and 9) which is secured to the horizontal plate I8. The circuits controlled by the cover 38 and the push button I13 will be described in connection with the circuit diagram of Fig. 21. For the present we need only say that when the starting button 113' is operated with the cover'closed, the driving motor I52 and the clutch solenoid 63 are energized.

' Thereupon the winding drum I35 is coupled to the motor-driven shaft I36 by the closed clutch I51 and the cord I34 is slowly wound up on the drum. At the same time the cylinder I1 is rotated at high speed and the scanning begins. We shall assume that the optical mechanism of the scanning carriage SK and the electric stylus 95 of the recording head RD are in operative condition.

Looking at the schematic view of Fig. 19, we see the scanning devices SK'and RD in their normal starting position. That is, the optical carriage SK starts at the point I16 near the top of the transparent cylinder I1 and the stylus 95 of the recording head RD starts near the bottom of the cylinder. As. the, drum I35 is rotated clockwise by the motor I52, itwinds up the cord I34 and thereby raises the recording head RD, which in turn pulls down the scanning carriage SK through the cable connection I24. The transmitting device SK and the receiving device RD are'thus operated simultaneously along the cylinder in opposite directions by tandem driving connections which are exceedingly simple and efiicient.

As the optical scanning point I15 travels down along the copy surface of the outer sheet 35, the electric recording point 95 travels upward at the same rate along the inner surface of the blank 36.. Through an electric transmission system to be explained in the, description of Fig. 21 the optically scanned copy on sheet 35 is electrically recorded in facsimile on sheet 36. In the particular machine we are describing the'cylinder l1 rotates at a speed of300 R. P. M. and the two scanning devices SK and RD travel vertically at a rate representing 100 scanning lines per inch. These figures are given merely by way of example.

It-should be noted (see Fig. 9) that the optical scanning point I16 and the recording point of stylus 95 operate in the same radial plane of cylinder [1. This means that the transmitting and recording devices of our machine are always in phase without the. need of separate phasing mechanism. In other words, the attendant does not have to bother about placing the sheets in a certain radial position within the cylinder. He simply' pushes the rolled-up sheets in without regard to where the overlapping ends may come. The scanning devices SK and RD have each a definite length of travel which is the same for both and is sufi-lcient'to cover'the entire copy surface of sheet 35. Comparing Figs. 12 and 13, it will be seen that theoptical scanning point of carriage SK travels straight down from its starting position I16 in Fig. 12m its final position I16" in Fig."13. The-transmitting'distance from I16 to I16 and the receiving distance from 95 to 95' are always equalfi This equality of movement is assured by the connectingm'etal cable I24 which has a substantially constant'lengthj On the other hand, the cord I34 which "connects the recording head RD with the drum I35 may be of woven threads so as to be very flexible and wind easily on andoff the drum. It would not matter at all if the cord I34 should stretch a little, for that would merely vary the distance of the connection between the drum I35 and the recording head RD without affecting the constant cable distance between the scanning devices RD and SK.

One of the practical advantages of our machine lies in the'fact that the cylinder I1 can be of any required size for scanning large sheets, such 'as l2 drawings and the like. So it will be evident that the distance traveled by the scanning devices SK and RD depends upon the length of cylinder I1. The machine shown in the drawings of this application was designed for standard sheets of 8 x 11 inches, so the dimensions of cylinder I1 were calculated accordingly. While the use of a larger cylinder would increase the height of-the machine, it would not affect the compactness of the machine as a piece of office equipment.

' When the optical scanning carriage SK reaches its final position as shown in Fig. 13, it strikes an arm I11 of a switch I18 which is mounted on the vertical guide rod 63. The position of switch I18 on this rod is readily adjusted to correspond to the final position of the scanning carriage as determined by the length of cylinder I1 in any particular design of machine. When the switch I18 is thus operated at the end of the scanning movement, the driving motor I52 and the clutch solenoid I64 are deenergized (as will be explained for Fig. 21) so that the cylinder I1 stops and the drum I35 is unclutched from the shaft I36.

The tensioned spring drums- 61 and 68 instantly pull the carriage SK back to normal position and at the same time the heavy recording head RD drops by gravity (perhaps also aided by the spring drums) to the bottom 'of the cylinder thereby rapidly unwinding the cord I34 from the released drum I35. The brake spring I19, as previously explained, keeps the drum from spinning too fast in unwinding the cord which might otherwise become tangled. To prevent the cord I34 from jumping the pulley I33, an arm I19 is fastened to the top of bracket I31 (Fig. 4) and extends under the pulley. The tip of this arm is bent laterally to form a guide I89 (Figs. 12 and 13) which lies across the pulley to enclose the cord.

The recording blanks 36 used in this machine are of such a nature that the operation of the electric stylus produces fumes or smoke which it is desirable to remove from inside the cylinder IT. For this purpose we provide an exhaust pipe I8I (Figs. 8 and 11) which extends into the rotary cylinder support 2i. The pipe I8I projects from a casing I82 which is mounted on top of an L- shaped bracket I83 by screws I84, as shown in Figs. 8 and 10, where it will be seen that the bracket I83 is fastened to the main base I2 by screws I85. Within the L-shaped bracket I83 is mounted a blower unit comprising an electric motor I86 and a suction fan I81 driven by the motor which is supported on posts I88 (Fig. 6) extending upward from the main base I2.

The frame of motor I carries a housing I89 for the fan I81 andthis housing communicates with the exhaust pipe I8I through casing I82, as shown in Figs. 8 and 11. The fan housing I89 has an outlet I90 opposite an aperture I9I in the bracket I83. As the fan I81 rotates it draws air through the openings 44 in the cover 38 and this downward draft in the cylinder carries oil the fumes through pipe I8I, casing I82 and the fan outlet I99. We usually put a screen or filler in casing I82 to deodorize the fumes.

Operational circuit diagram of Fig. 21

The source of power for the machine is usually a -volt GO-cycle alternating current which is indicated in the diagram by a pair of terminals or bus bars A and B. In describing the circuits we shall use the term "wire to mean any kind of electrical connection. The labeled rectangles I 92, I93 and I94 represent respectively a preamplifier, a combined regulator-inverter, and a 

